With development of high-definition digital televisions and high-end multimedia information systems, people impose higher and higher requirements on visual effects of a video source. Therefore, a frame rate of an existing video program source needs to be increased to accomplish better visual effects. Meanwhile, with more and more bandwidth resources being allocated and occupied, most video applications can only obtain very limited bandwidth resources, and a time resolution generally needs to be reduced on an encoder end by discarding a frame, so as to meet the bandwidth requirement, and a decoder end recovers the discarded frame by interpolating the frame, so as to improve video quality.
A video frame interpolation technology, that is, a frame rate up-conversion (Frame Rate Up-Conversion, FRUC) technology, elevates a low frame rate of a video to a high frame rate by interpolating an intermediate frame between two adjacent frames on the decoder end, and implements conversion between different frame rates.
Motion estimation methods are primarily categorized into a unidirectional motion estimation method and a bidirectional motion estimation method. A unidirectional motion estimation method may lead to a problem of “overlap” and “void” of the interpolated frame, and a bidirectional motion estimation method uses a to-be-interpolated frame as a mirror center, which prevents the problem of “overlap” and “void” of the interpolated frame in the motion compensation processing. In the bidirectional motion estimation method in the prior art, a search algorithm in video compression, such as a three-step search algorithm and a diamond search algorithm, is applied in motion estimation. However, as different from video compression, time-space correlation exists between motion vectors due to continuity of motion of video objects, and the use of the search algorithm in the video compression makes the interpolated frames of motion compensation generate image information inconsistent with subjective visual perception. Therefore, accuracy of motion vectors of estimated interpolated blocks is low, which also reduces image quality.